Dan D'Agostino Momentum amplifier- which preamp?

Anyone run Dan's amp (or amps) with linestage pre from other manufacturers?

I tried Dan's gear (integrated and separates) with my Rockport Aviors. Amazing in many ways, but lacked the palpably real presence of "vocalist in the room" that the best tubes provide. Anyone run Dan's amp(s) with a tube preamp?

Thanks, looking for that last (or at least the next last) final system.